loop-skills: Instructions file for Claude Code

AGENTS.md

loop-skills AGENTS.md is an instructions file for Claude Code, Codex, OpenCode from donnfelker/loop-skills. It costs 1,257 tokens per session, scanned A, original, MIT.

Repository instructions for a collection of agent skills packaged as a Claude Code plugin marketplace.

In plain words
What is it for?
Use them when creating, packaging, or maintaining skills and plugins in the loop-skills repository.
Why use it?
They explain the required folder structure, metadata, workflow principles, and development checks.

Instructions file for Claude CodeCodexOpenCode

Written for Claude Code and Codex and OpenCode: ${CLAUDE_PLUGIN_ROOT} variable, but also the file is AGENTS.md. Also seen: mentions .claude-plugin; mentions Claude Code; mentions AGENTS.md.

This is donnfelker/loop-skills's own configuration. It tells Claude Code, Codex and OpenCode how to work on loop-skills itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything loop-skills configures →

Runs only inside a plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else, and the catalogue could not identify which plugin ships it.

Reuse

Borrowing it

Nothing to install: this file belongs to donnfelker/loop-skills. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/donnfelker/loop-skills/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/donnfelker/loop-skills

Made for: Claude Code, Codex, OpenCode.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for loop-skills AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/donnfelker/loop-skills/agents-md/github.svg)](https://agentmods.dev/instructions/donnfelker/loop-skills/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/donnfelker/loop-skills/agents-md"><img src="https://agentmods.dev/badge/instructions/donnfelker/loop-skills/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for loop-skills AGENTS.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/donnfelker/loop-skills/agents-md"><img src="https://agentmods.dev/badge/instructions/donnfelker/loop-skills/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 1,257 This file is loaded in full into every session.
When invoked 1,257 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.01257 $0.01257
Opus 5.5 $0.00503 $0.00503
Sonnet 5.5 $0.00251 $0.00251
Haiku 4.5 $0.00126 $0.00126

Measured 1mo ago against content hash 4e54b0118d75, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

loop-skills AGENTS.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

AGENTS.md · 98 lines

How it starts

The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

Guidelines for AI agents working in this repository.

Repository Overview

This repository contains Agent Skills following the Agent Skills specification, packaged as a Claude Code plugin marketplace via .claude-plugin/marketplace.json.

Every plugin here is a bounded autonomous loop: it drives an artifact to a terminal state, checks an explicit termination condition (quiet round, two clean passes, a cap), and commits per round for an audit trail.

Repository Structure

plugins/
└── plugin-name/
    ├── .claude-plugin/
    │   └── plugin.json        # Plugin manifest (name, description, version, license)
    ├── references/            # Optional - plugin-wide docs cited via ${CLAUDE_PLUGIN_ROOT}/references/...
    └── skills/
        └── skill-name/
            ├── SKILL.md       # Required skill file (<500 lines)
            ├── references/    # Optional - skill-local docs loaded on demand
            ├── scripts/       # Optional - executable code
            └── assets/        # Optional - templates, data files

Build / Lint / Test Commands

Skills are content-only (no build step). Validate with:

./validate-skills.sh plugins/*/skills/

Manually verify: YAML frontmatter is valid; name matches the directory exactly; name is 1-64 chars, lowercase alphanumeric and hyphens; description is 1-1024 characters.

Required Frontmatter

---
name: skill-name
description: What this skill does and when to use it. Include trigger phrases.
---
Field Required Constraints
name Yes 1-64 chars, lowercase a-z, numbers, hyphens. Must match dir.
description Yes 1-1024 chars. Describe what it does and when to use it.
license No License name (default: MIT)
metadata No Key-value pairs (author, version, etc.)

Read the full file on GitHub · 98 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 1mo ago First seen · 98 lines · 1,257 tokens per session scan A 4e54b0118d75

Subscribe to this mod's changes

loop-skills AGENTS.md is an instructions file published in the GitHub repository donnfelker/loop-skills (19 stars, last pushed 2mo ago), licensed MIT. It adds 1,257 tokens to every session, about $0.0050 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other instructions, from other repositories

vscode buildNext.instructions.md

Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).

microsoft/vscode · 9,649 tokens

next.js AGENTS.md

AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.

vercel/next.js · 7,384 tokens

vscode oss-third-party-notices.instructions.md

Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).

microsoft/vscode · 5,262 tokens

langchain AGENTS.md

AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.

langchain-ai/langchain · 4,680 tokens

vscode copilot-instructions.md

Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).

microsoft/vscode · 2,731 tokens

deno copilot-instructions.md

Copilot instructions for denoland/deno, covering deno development guide for github copilot, network access, high level overview, key directories and key files to understand first.

denoland/deno · 3,077 tokens